Torpedo director



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Dec. 18, 1945.

E. A. SPERRY, JR, ET AL TORPEDO DIRECTOR Filed July 25, 1940 4Sheets-Sheet 3 mm x 0M6. E M m 55.0, o WA flT R T If A MM FIG.3.

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TORPEDO DIRECTOR Filed July 25, 1940 4Sheets-Sheet 4 INVENTORS ELMERA.are/mm J6- Q'JEUIVH'. l l'libML. IWQ l HUWILN to.

Patented Dec. 18, 1945 UNITED STATES PATENT OFFICE TORPEDO DIRECTOR NewYork Application July 25, 1940, Serial No. 347,354

2 Claims.

This invention relates to an instrument commonly termed a torpedodirector, whose function it is to control the directionorfiringhitorpedoes from war s. While large, complicated and expensi'm oi gedo directors are known and in use on battle ships and destroyers,these devices would not be suitable for use upon the new class of small,high-speed motor torpedo boats which have recently been introduced.These boats operate at high speeds and are subject to rapid deviationsfrom course. Furthermore, they are built so low on the water-line thatit Would be impossible to estimate the speed and direction of the targetship-a condition precedent to the use of standard torpedo directors.

It is the principal object of this invention, therefore, to provide asmall and simplified torpedo director particularly adapted for the motortorpedo boats mentioned above, which will be accurate in operation athigh speed, in high seas, or when zigzagging if battle conditions sorequire, and which operates on a principle which provides a simple,rapid and accurate solution of the triangle of torpedo fire without thenecessity of accurately gauging the target course and speed.

It is a further object of this invention to provide a torpedo directorwhich will facilitate cooperation between the commanding ofiicer who isoperating the torpedo director and the helmsman who is steering theship, without the necessity of conversations, either direct or bytelephone.

Further objects and advantages of this invention will become apparent inthe following detailed description thereof.

In the accompanying drawings:

Fig. 1 is a front elevation of a torpedo director embodying theprinciples of this invention.

Fig. 2 is a vertical section through the device shown in Fig. 1.

Fig. 3 is a section taken substantially on the line 33 of Fig. 2.

Fig. 4 is a vertical section taken substantially on the line 4-4 of Fig.2.

Fig. 5 is a graph illustrating the theory of this invention.

Referring first to Fig. 5, the theory underlying the present inventionis graphically illustrated. Let us assume that a target ship istraveling along a course T1T2T3 and that a firing vessel on which thetorpedoes are carried and on which the torpedo director is mounted, istraveling a course F1F2F3. If the target ship and the firing ship aretraveling at the proper speeds they will collide at point C, in whichcase it is said that the firing ship is traveling on a collision course.If a sight instrument S on the firing ship is directed on the targetship, it will make an angle 0 with the line of travel of the firingship. If the firing ship is traveling a collision course, then,obviously, at every point along its course the sight instrument S willremain trained on the target ship because the triangles CTsFa, CT2F2 andCT1F1 are all similar triangles. If, however, the firing ship istraveling too slow or too fast to meet the target ship at C, there willbe no collision and the firing ship will pass behind or in front of thetarget ship as their courses cross. When the sight instrument is turnedon the target ship, the commanding officer on the firing ship can seealmost immediately whether he is traveling on a collision course,because from the above theory it becomes apparent that if he is on thecollision course the sight instrument will remain trained on the targetship. If he is not on the collision course, the target ship will passbehind or in front of the line of sight. When this occurs, it isnecessary for the commanding ofiicer to change the course of the firingship so as to increase or decrease the angle 0, as the case may be, orto alter the speed of the firing ship, until he reaches the conditionwhere the line of sight remains trained on the target ship.

Having thus achieved a collision course, the firing ship is ready forthe next step, which is, directing the ship into the torpedo course. Itis apparent that if the torpedo is designed to travel at the same speedas the firing ship, or, conversely, if the firing ship is purposelyoperated at the known torpedo speed, then it is only necessary to slowdown the firing ship for an instant and discharge the torpedoes whichthen continue on the collision course previously determined and willcollide with the target ship in the same manner as the firing ship wouldhave collided with the target ship if it had continued on its course topoint C. Usually, however, the torpedo will have a, different speed fromthat of the firing ship, and under these conditions it will be seen thatin order for the torpedoes to effect collision with the target ship itis necessary to turn the boat, when the torpedoes are fired, to adifferent angle from the collision course of the firing ship. Thedirection of the correction to be introduced in the course of thetorpedoes depends upon whether the torpedoes travel faster or slowerthan the firing ship. If they travel faster, then a correction angle oris introduced in order that the torpedo may meet the target ship soonerat collision point C. If, however, the torpedoes travel slower than thefiring ship, then a correction angle 5 is introduced in the oppositedirection to correction angle so that the torpedo will collide with thetarget ship later, that is, at point C".

The operations described above may be summarized as follows:

1. The commanding officer must place his sight on the target ship.

2. The commanding ofiicer must indicate the changes in the course of thefiring ship in order that the sight instrument shall remain on thetarget ship-in other words, in order that a collision course may beeffected.

3. The helmsman must direct the ship promptly into the collision course.

4. The commanding officer must indicate to the helmsman the necessarychange in course for torpedo travel.

5. The helmsman must turn the ship into the torpedo course.

6. The commanding officer must release the torpedoes when the torpedocourse is reached.

This mechanism has been designed for the purpose of effecting the aboveoperations quickly and efficiently with the simplest mechanism, withmaximum cooperation between the commanding ofiicer andthe helmsmanwithout the necessity of conversation between them, and under thespecial conditions to which the small motor torpedo boats are subjected,namely, high speeds and heavy seas and a low platform of operation fromwhich it is impossible to gauge with any accuracy the target direction,target angle, or target speed.

It will be noted that in the sequence of operations noted above, thefirst of these is to train a sight on the target ship. The sightsheretofore employed are not feasible for use upon motor torpedo boatsbecause of the speed, rapid variations in direction, vibration, and lowplatform of operations of such boats. Since everything depends upon thespatial direction of the line of sight remaining constant, becauseotherwise it would be impossible to tell when the firing ship istravelling a collision course, a line of sight stabilized in azimuth isessential to a torpedo director for this type of boat. For this purpose,We em a zsviie e psiie at lfl ifid c'dihprising rotor mounted forrotation in a vertical plane around the horizontal axis |2 within gimbalring I3 pivoted on horizontal axis |4 within a ring |5 which is pivotedfor rotation within casing IS on vertical axis Integral with the ring I5is a vertical shaft 20 extending upwardly into a cylindrical transparentcasing 2| and carrying at its upper end a spider 22 which carries atdiametrically opposite ends a sight mechanism consisting of a verticalbar 24 at one end and a V-shaped sighting member 25 at the diametricallyopposite end. The rotor may be spun in any convenient manner, as, forinstance, by air directed against turbine buckets in its periphery bymeans of a jet through which air is driven in well known manner. Thedirector gyro ll, if spun rapidly enough, will maintain its verticalplane and therefore its position in azimuth wherever it happens to beplaced in azimuth. Therefore, the sight instrument 24, 25 will maintainits line of sight in azimuth regardless of the deviations from course ofthe vessel. For rotating the sight mechanism so that the line of sightmay be adjusted on the target ship, a spring pressed plunger 30 (seeFig. 4) may be operated to cause gear 3| to engage a gear 32 on ring l5,whereby the said ring may -be rotated around vertical axis ll. Anysuitable locking or caging means (not shown) may be provided for lockingthe gyro about its horizontal axis to prevent precession when knob 30 isoperated. The gyro rotor, and therefore the line of sight, will hold itsposition in azimuth regardless of ship deviations, and thereforevibration of the boat, rapid deviations from course, yawing, and theeffect of high seas, will not operate to displace the line of sight.

The helmsman first places the ship approximately on the collision courseso that the later corrections in the ships course will be minimized.After having sighted on the target ship, the next duty of the commandingofficer is to try to effect a collision course by his own ship, in otherwords, such course that the line of sight without further adjustmentremains on the target. For this purpose he may have to indicate to thehelmsman a change of course in one direction or the other, and he doesthis by means of a match-the-pointer system, as follows: The spider 22carries a pointer 40. If desired, a plurality of such pointers may becarried, preferably at intervals, so that the helmsman can see thepointer from various positions with respect to the torpedo director. Asecond pointer 4| is carried by a vertical ring 42 which is supported ona plate 43 adapted to be frictionally rotatable around a Vertical axison a plate 44 fixed to the casing I6. The frictional engagement of plate43 with plate 44 may be effected by means of upper and lower flanges 45and 46. The pointers 40 and 4| are matched initially. When the commanderhas placed his sight on the target ship and the target ship moves awayfrom the sight in one direction or the other, the commanding officerknows that the direction of his own ship must be changed in onedirection or the other to effect collision course. He therefore takeshold of ring 43, either directly or by taking hold of knob 50 (which isfor an additional purpose to be described hereinafter), and. rotatesring 43 around the vertical axis until pointer 4| shows a correction tothe right or left of pointer 40. Since pointer 4| is carried by ring 42,which is frictionally held to casing l6 so that it normally moves withthe ship, the helmsman will correct the course of the vessel merely byapplying the helm in one direction or the other to bring the pointers 40and 4| into matching or coincident relationship. When these pointers arebrought into matching position, the commanding ofllcer can then seewhether his sight 24, 25 remains on the target ship; in other words,whether he has applied the proper correction. If the target ship stillmoves out from the line of sight, the commanding officer moves ring 42to indicate an additional correction to the helmsman who then operatesthe ship to bring the pointers into coincidence. When, finally, the lineof sight stays fixed on the target ship, the commanding ofiicer knowsthat he is on a collision course and his next concern is setting thecourse of his firing ship in the proper direction for the release of thetorpedoes. As hereinbefore stated, if the torpedo speed is the same asthe firing ship speed, then it is only necessary to close the throttlesof the firing ship for an instant to slow down the ship while thetorpedoes are discharged, and the latter will follow the same course asthe firing ship does, namely the collision course. If, however, thetorpedo travels faster or slower than the firing ship, then a correctionin firing course, either of the nature of angle or angle 5 is necessary.The commanding ofiicer has a chart from Which he can read off the propercorrection to be intro- Pet-m duced, said correction being a functionnot only of the difference between firing ship speed and target speed,but also of the angle 0. He then turns knob 50 on the end of a shaft 5|having a worm and gear connection 52, 53 with a shaft 54 carrying at itsupper end a spider 55 having a plurality of pointers 56 adapted tocooperate with pointers 40 and 4|. The pointer 56, which may be of adifferent color, and which is matched initially with pointers 40 and 4|,is operated to the right or left of pointer 4| and the helmsman nowsteers his ship to effect coincidence of pointers 40 and 56. When thiscoincidence is effected, in other words, when these pointers arematched, the ship is on the proper torpedo course necessary to effectcollision between the torpedo and the target ship. Yawing of the firingship, or zigzagging to avoid enemy fire, will not interfere with theproper launching of the torpedoes, because the commanding oflicer canwait until these pointers approach coincidence and. at that instant hecan push the buttons which release the torpedoes.

The torpedo director may be mounted upon any suitable base 60 fixed tothe firing ship, and may be mounted on said base 60 by means ofadjustable supports 5|, 62, 63, so that the director may be properlyleveled.

In accordance with the provisions of the patent statutes, we have hereindescribed the principle and operation of our invention, together withthe apparatus which we now consider to rep-resent the best embodimentthereof, but we desire to have it understood that the apparatus shown isonly illustrative and that the invention can be carried out by otherequivalent means. Also, while it is designed to use the various featuresand elements in the combination and relations described, some of thesemay be altered and others omitted without interfering with the moregeneral results outlined, and the invention extends to such use.

Having described our invention, what we claim and desire to secure byLetters Patent is:

1. In a torpedo director for ships, in combination, a line of sightdevice adapted to be actuated by an operator, means fonstahilizing saiddevice in any position in azimuth in which it is placed, a pointer fixedto said sight device, a second pointer supported on said ship formovement similar to said first pointer, means for setting said secondpointer relative to the ship for collision course correction asdetermined by the observed direction and rate of movement of the targetrelative to the line of sight whereby the ship may be steered tocollision course by maintaining said pointers in coincidence.

2. In a torpedo director for ships, in combination, a line of sightdevice adapted to be actuated by an operator, means for stabilizing saiddevice in any position in azimuth in which it is placed, a pointer fixedto said sight device, a second pointer supported on said ship formovement similar to said first pointer, means for setting said secondpointer relative to the ship for collision course correction asdetermined by the observed direction and rate of movement of the targetrelative to the line of sight whereby the ship may be steered tocollision course by maintaining said pointers in coincidence, a thirdpointer supported on the ship for movement similar to said firstpointer, and means for setting said third pointer relative to the'shipand to said second pointer for torpedo course correction whereby saidship may be steered to torpedo course as indicated when said thirdpointer and said first pointer coincide.

ELMER A. SPERRY, JR. JOHN D. PEACE, JR.

